rgw: change cache / watch-notify init sequence

Fixes: #6046
We were initializing the watch-notify (through the cache
init) before reading the zone info which was much too
early, as we didn't have the control pool name yet. Now
simplifying init/cleanup a bit, cache doesn't call watch/notify
init and cleanup directly, but rather states its need
through a virtual callback.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit d26ba3ab0374e77847c742dd00cb3bc9301214c2)

3 files changed, 16 insertions, 5 deletions

diff --git a/src/rgw/rgw_cache.h b/src/rgw/rgw_cache.h
index b6c4e15eede..601fcdfc963 100644
--- a/src/rgw/rgw_cache.h
+++ b/src/rgw/rgw_cache.h
@@ -177,14 +177,13 @@ class RGWCache  : public T
     if (ret < 0)
       return ret;
 
-    ret = T::init_watch();
-    return ret;
+    return 0;
   }
 
-  void finalize() {
-    T::finalize_watch();
-    T::finalize();
+  bool need_watch_notify() {
+    return true;
   }
+
   int distribute_cache(const string& normal_name, rgw_obj& obj, ObjectCacheInfo& obj_info, int op);
   int watch_cb(int opcode, uint64_t ver, bufferlist& bl);
 public:
diff --git a/src/rgw/rgw_rados.cc b/src/rgw/rgw_rados.cc
index 222b79a7d2e..0bbbf177b7a 100644
--- a/src/rgw/rgw_rados.cc
+++ b/src/rgw/rgw_rados.cc
@@ -817,6 +817,9 @@ void RGWRadosCtx::set_prefetch_data(rgw_obj& obj) {
 
 void RGWRados::finalize()
 {
+  if (need_watch_notify()) {
+    finalize_watch();
+  }
   delete meta_mgr;
   delete data_log;
   if (use_gc_thread) {
@@ -909,6 +912,14 @@ int RGWRados::init_complete()
     }
   }
 
+  if (need_watch_notify()) {
+    ret = init_watch();
+    if (ret < 0) {
+      lderr(cct) << "ERROR: failed to initialize watch" << dendl;
+      return ret;
+    }
+  }
+
   map<string, RGWZone>::iterator ziter;
   for (ziter = region.zones.begin(); ziter != region.zones.end(); ++ziter) {
     const string& name = ziter->first;
diff --git a/src/rgw/rgw_rados.h b/src/rgw/rgw_rados.h
index d01f76ec224..e6ab244afa9 100644
--- a/src/rgw/rgw_rados.h
+++ b/src/rgw/rgw_rados.h
@@ -1254,6 +1254,7 @@ public:
   virtual int update_containers_stats(map<string, RGWBucketEnt>& m);
   virtual int append_async(rgw_obj& obj, size_t size, bufferlist& bl);
 
+  virtual bool need_watch_notify() { return false; }
   virtual int init_watch();
   virtual void finalize_watch();
   virtual int distribute(const string& key, bufferlist& bl);